Generating Force Vectors from Projective Truncated Signed Distance Fields for Collision Avoidance and Haptic Feedback

Signed Distance Fields are a common surface representation method widely used for both 3D mapping and obstacle avoidance. While the former traditionally uses projective Truncated Signed Distance Fields (TSDF), the latter often requires a complete Euclidean Signed Distance Field (ESDF) representation of the environment. In this paper, we propose a unified system by combining both methods to generate force vectors to nearby obstacles from a TSDF-based 3D reconstruction. We introduce a new merging scheme to better capture the geometry of the object, with no post-processing requirements, and a way to increase the effective range of the system. Validation experiments demonstrate the accuracy of the force vector calculation by comparing it against an ideal simulated environment. The flexibility of the system is demonstrated by implementing a haptic feedback teleoperation setup, which is validated through a user study in a teleoperation task. Through this, it is shown that the proposed method provides a statistically significant improvement to the task. Finally, a brief description on future improvements to the system is presented.